1. Field of the Invention
This invention relates to a polymer film that performs well in terms of stable liquid repellency as well as adhesion to base materials, hardness and abrasion resistance, to a liquid-repellency treatment solution of good film formability highly adapted to forming such high quality film, to a polymeric compound to be used for such a treatment solution and also to a method of manufacturing such a polymeric compound.
The present invention also relates to a surface-modifying method to provide the surface of an article with stable liquid repellency by using a single resin ingredient system, and preferably, to form films that are advantageous in terms of stable liquid repellency as well as adhesion to the base material, hardness and abrasion resistance and also to a surface-modified article.
The present invention additionally relates to an ink-jet recording head for forming an image on a recording medium by ejecting ink droplets highly adapted to form a stably liquid-repellent film (that is, preferably, also highly adherent to the base material, hard and abrasion-resistant), to a method of manufacturing a discharge orifice plate to be used for such an ink-jet recording head and also to an ink-jet recording apparatus. An ink-jet recording head according to the invention can particularly suitably be applied to an ink-jet recording apparatus that uses mechanical energy generated by means of piezoelectric elements or thermal energy obtained by means of an electrothermal converter as energy for ejecting ink droplets and recording dots on the recording medium.
2. Related Background Art
Methods for applying a liquid composition adapted to introduce desired properties onto the surface of a base material are used as an embodiment of the method of modifying the surface of the base material of an article that is devoid of such properties. Articles to the surface of which such a liquid-repelling agent is applied include various goods for daily life, water pipes and so on as well as an ink-jet head of an ink-jet recording apparatus that are adapted to use a liquid-repellent solution for recording images. For instance, as ink accumulates near the discharge orifices on the discharge orifice plane for discharging ink that is arranged on an ink-jet head, there can arise problems including ink slippage along the ink discharge direction on the formed image and clogged discharge orifices. Therefore, it is a general practice to apply a liquid-repelling agent to the discharge orifice plane where the discharge orifices are arranged.
For example, Japanese Patent Application Laid-Open No. 10-053639 describes a fluorine type liquid-repelling agent in a liquid state that is a fluorine-containing epoxy resin composition containing (a) a multifunctional epoxy resin having two or more epoxy groups in a molecule and not containing F nor Si by 5 to 80 parts by weight, (b) an epoxy compound having a perfluoro group at the terminal by 5 to 40 parts by weight and (c) a compound having two or more epoxy groups, two or more alcohol groups, two or more carboxylic acid groups and/or two or more amine groups in a molecule and also containing F or Si by 5 to 80 parts by weight.
Japanese Patent Application Laid-Open No. 08-132614 discloses an electrically insulating resin film formed on the inner wall of the nozzle and the flow path of an ink-jet head that is acryl type electrodeposition resin containing fine particles of a fluorine resin.
However, of the above cited prior art, the electrically insulating resin film disclosed in Japanese Patent Application Laid-Open No. 08-132614 is composed of a film formed simply by adding liquid-repellent fluorine resins to the film in a mixed state. Therefore, the liquid repellency of the film is gradually reduced and the modified surface of the film gradually loses the uniformity of its advantageous properties if the surface of the resin film is held in an abrasive environment.
On the other hand, while ingredients of the fluorine-containing epoxy resin composition described in Japanese Patent Application Laid-Open No. 10-053639 show compatibility in a dissolved state, their distribution can become varied on the applied film depending on the conditions of application to produce a specific distribution pattern of liquid repellency in the applied film. Additionally, the ingredients have to be held in an evenly mixed condition when the composition is in a dissolved state to consequently make it very difficult to control the storage of the solution.
Besides fluorine type liquid-repelling agents in a liquid state, liquid-repelling agents containing silicon are also known. However, silicon is found on the surface of the liquid-repellent film formed by a silicon-containing liquid-repelling agent so that the liquid-repelling effect of the film is reduced if the liquid-repellent film is abraded repeatedly.
As a result of a series of intensive research efforts looking into the prior art, the inventors of the present invention came to find that the prior art surface-modifying techniques are insufficient for improving the liquid repellency to maintain the liquid-repelling effect of a liquid-repelling agent. Additionally, there is a strong demand not only in the field of ink-jet recording but also in various technological fields for improved surface-modifying methods that can enhance the liquid repellency of the surface to maintain the liquid-repelling effect. For instance, such improved methods will find applications in the field of treating the outer walls of buildings.
Therefore, it is an object of the present invention to provide a novel polymer film that is based on a principle totally different from that of the known liquid-repelling agents used with the known surface-modifying methods and can easily modify the properties of the surface of an article, More specifically, such a polymer film can be formed on the surface of an article by application to improve the liquid repellency of the surface of the article to maintain the liquid-repelling effect.
Another object of the present invention is to provide a liquid-repellency treatment solution containing a novel polymeric compound that can be used for forming a polymer film according to the invention and showing an excellent liquid-repelling effect.
Still another object of the present invention is to provide a method of manufacturing a novel macro-monomer that can be used for synthetically producing a polymeric compound that can by turn be used for forming a polymer film according to the invention and showing an excellent liquid-repelling effect and also a method of manufacturing a graft polymeric compound by using such a novel macro-monomer.
Still another object of the present invention is to provide a surface-modifying method adapted to provide the surface of an article with a film coat that operates excellently in terms of liquid repellency and film formability as well as adhesion to articles, hardness and abrasion resistance, and also to provide a surface-modified article.
Still another object of the present invention is to provide a surface-modifying method adapted to form an excellent film coat, which can be processed by using light energy such as an excimer laser.
Still another object of the present invention is to provide an ink-jet recording head having an excellent discharge orifice plane in terms of liquid repellency (and, preferably, adhesion to the base material of the discharge orifice plane as well as hardness and abrasion resistance) prepared by applying a liquid-repelling agent according to the invention, in which the liquid repellency and the like can be maintained without being reduced by use, and also an Ink-jet recording apparatus comprising such an ink-jet recording head.
A further object of the present invention is to provide a method of manufacturing a discharge orifice plate to be used for an ink-jet recording head to easily obtain the latter having a discharge orifice plane provided with a highly liquid-repellent film coat preferably by using light energy such as an excimer laser.
The above objects are achieved by the present invention. In one aspect of the invention, there is provided a polymer film including a polymer chain containing fluorine atom wherein the polymer film has a physical aggregate (domain) of the polymer chain in the inside and/or on the surface thereof.
In another aspect of the invention, there is provided a polymer film composed of a single polymeric compound comprising first segments containing fluorine atoms and second segments different from the first segments in terms of affinity for solvents, including aggregates of the polymeric compound formed in the inside and/or on the surface thereof by physical crosslink between the first segments.
In still another aspect of the invention, there is provided a polymer film composed of a single polymeric compound comprising first segments containing fluorine atoms and second segments different from the first segments in terms of affinity for solvents, including an aggregate of the polymeric compound formed by physical crosslink between the first segments, the second segments being mutually chemically crosslinked.
In still another aspect of the invention, there is provided a liquid-repellency treatment solution dissolving a polymeric compound having a polymer chain containing fluorine atoms, wherein the solution contains a physical aggregate of the polymer chain.
In still another aspect of the invention, there is provided a liquid-repellency treatment solution containing a single polymeric compound, dissolved in a solvent, comprising first segments containing fluorine atoms and second segments different from the first segments in terms of affinity for the solvent; and an aggregate of the polymeric compound formed by physical crosslink between the first segments.
In still another aspect of the invention, there is provided a surface-modified article having liquid repellency, having a polymer film provided on the surface, the polymer film including a polymer chain containing fluorine atoms, and a physical aggregate of the polymer chain in the inside and/or on the surface thereof.
In still another aspect of the invention, there is provided a surface-modified article having liquid repellency, having a polymer film provided on the surface, the polymer film being composed of a single polymeric compound comprising first segments containing fluorine atom and second segments different from the first segment in terms of affinity for solvents, including an aggregate of the polymeric compound in the inside and/or on the surface thereof by physical crosslink between the first segments.
In still another aspect of the invention, there is provided a surface-modifying method comprising the steps of applying to the surface of an article a liquid-repellency treatment solution dissolving a polymeric compound having a polymer chain containing fluorine atom and a physical aggregate of the polymer chain; and drying the solution.
In still another aspect of the invention, there is provided a surface-modifying method comprising the steps of applying to the surface of an article a liquid-repellency treatment solution of a single polymeric compound, dissolved in a solvent, comprising first segments containing fluorine atoms and second segments different from the first segments in terms of affinity for the solvent, an aggregate of the polymeric compound formed by physical crosslink between the first segments; and drying the solution.
In still another aspect of the invention, there is provided a polymeric compound comprising a first segment containing fluorine atoms and a second segment different from the first segment in terms of affinity for solvents, wherein the first segment has a structure selected from the group consisting of general formulas (1) through (4) below, and the second segment has a structure selected from the group consisting of general formulas (5) and (6) and the chemical formulas of compounds  less than 1 greater than  through  less than 4 greater than  listed below:
first segments: 
in which in general formulas (1) through (4),
R=H or CH3,
RF1=xe2x80x94CF2xe2x80x94(xe2x80x94CF2xe2x80x94)n1xe2x80x94CF3, 
each of n1, n2 and n3 is independently an integer between 1 and 10;
second segments: 
in which n is a positive integer;
 less than 1 greater than : glycidyl(meth)acrylate,
2-glycidyl(meth)acrylate,
allylglycidyl(meth)acrylate,
allyl-2-methylglycidyl(meth)acrylate, 
 less than 2 greater than : vinyltrimethoxy silane,
vinyltriethoxy silane and other vinyl type silane coupling agents,
xcex3-(meth)acryloxypropyltrimethoxysilane,
xcex3-(meth)acryloxypropyltriethoxysilane,
 less than 3 greater than : dimethylaminoethyl(meth)acrylate,
dimethylaminopropyl (meth) acrylate,
acrylic acid,
methacrylic acid,
maleic acid,
fumaric acid,
vinyl acetate,
styrene carboxylate,
 less than 4 greater than  2-hydroxymethyl(meth)acrylate,
2-hydroxyethyl(meth)acrylate,
3-chloro, 2-hydroxypropyl(meth)acrylate,
allylphenol.
In still another aspect of the invention, there is provided a method of manufacturing a macro-monomer containing a perfluoroalkyl group having an ethylenically unsaturated group at the terminal thereof, comprising the step of reacting an oligomer containing a perfluoroalkyl group having a carbooxyl group at the terminal thereof with an epoxy compound containing an ethylenically unsaturated group.
In still another aspect of the invention, there is provided a method of manufacturing a graft polymeric compound comprising the step of copolymerizing a macro-monomer containing a perfluoroalkyl group having an ethylenically unsaturated group at the terminal thereof and a monomer containing an aromatic ring having a functional group capable of radical polymerization.
In still another aspect of the invention, there is provided the method of manufacturing a graft polymeric compound according to above paragraph, wherein
the monomer containing an aromatic ring is at least one selected from the group consisting of a phenyl group, a naphthyl group and a heterocyclic group.
In still another aspect of the invention, there is provided a method of manufacturing a macro-monomer containing acromatic rings having an ethylenically unsatrurated group at the terminal thereof comprising the step of reacting an oligomer containing an aromatic ring having a carboxyl group at the terminal thereof with an epoxy compound containing an ethylenically unsaturated group.
In still another aspect of the invention, there is provided a method of manufacturing a graft polymeric compound comprising a step of copolymerizing a macro-monomer containing aromatic rings having an ethylenically unsaturated group at a terminal and a monomer containing perfluoroalkyl group having a functional group capable of radical polymerization.
In still another aspect of the invention, there is provided a method of manufacturing a graft polymeric compound comprising the step of copolymerizing a macro-monomer having an ethylenically unsaturated group at the terminal thereof and an aromatic-ring-containing monomer having a functional group capable of radical polymerization and a perfluoroalkyl group.
In still another aspect of the invention, there is provided a method of manufacturing a crosslinked graft polymeric compound comprising the steps of providing a graft copolymer by copolymerizing a macro-monomer having an ethylenically unsaturated group at the terminal thereof and a crosslinkable functional group in the molecule with a monomer containing a perfluoroalkyl group and a functional group capable of radical polymerization; and crosslinking the functional group of the graft copolymer originating from the macro-monomer.
In still another aspect of the invention, there is provided an ink-jet recording head comprising an ink discharge orifice plane having a plurality of ink discharge orifices arranged thereon, including first regions having a predetermined affinity for water and second regions having an affinity for water different from that of the first region, the first regions and the second regions existing alternately along the peripheries of the ink-jet discharge orifices.
In still another aspect of the invention, there is provided an ink-jet recording head comprising an ink discharge orifice plane having a plurality of ink discharge orifices arranged thereon, having a polymer film provided thereon including polymer chains containing fluorine atoms, and physical aggregates of the polymer chains in the inside and/or on the surface of the polymer film.
In still another aspect of the invention, there is provided an ink-jet recording head comprising an ink discharge orifice plane having a polymer film provided thereon, compoosed of a single polymeric compound having first segments containing fluorine atom and second segments different from the first segments in terms of affinity for solvents, including an aggregate of the polymeric compound in the inside and/or on the surface of the polymer film by physical crosslink between the first segments.
In still another aspect of the invention, there is provided a method of manufacturing a discharge orifice plate to be used for an ink-jet recording head, comprising the steps of: (i) forming on one of the surfaces of a plate member a polymer film which includes a polymer chain containing fluorine atoms, and a physical aggregate of the polymer chain in the inside and/or on the surface thereof, and absorbs light with a predetermined wavelength range; and (ii) irradiating the plate member resulting from the step (i) with light of the wavelength range to be absorbed by the polymer film to produce a through-hole in the plate member.
In still another aspect of the invention, there is provided a method of manufacturing a discharge orifice plate to be used for an ink-jet recording, comprising the steps of: (i) forming on one of the surfaces of a plate member a polymer film which is composed of a single polymeric compound having first segments containing fluorine atoms and second segments different from the first segments in terms of affinity for solvents, includes an aggregate of the polymeric compound in the inside and/or on the surface thereof by physical crosslink between the first segments, and absorbs light with a predetermined wavelength range; and (ii) irradiating the plate member resulting from the step (i) with light of the wavelength range to be absorbed by the polymer film to produce a through-hole in the plate member.
In a further aspect of the invention, there is provided an ink-jet recording head comprising a discharge orifice for discharging ink, ink flow paths communicating with the discharge orifice, a discharge energy generating element arranged in the ink flow path for the purpose of generating energy to be used for discharging ink and a discharge orifice plate jointed to the orifice plane carrying the orifice communicating with the ink flow path, the discharge orifice plate being obtained by the method of manufacturing a discharge orifice plate to be used for an ink-jet recording according to the invention.